Combine soy sauce, water, brown sugar, ground pepper, and garlic in a bowl. Stir until sugar is dissolved.

In a big bowl, toss together beef strips and cornstarch until all sides of the meat are fully covered.

In a wok or saute pan, heat oil over high. Add in beef slices and stir-fry for about 2-3 minutes. Do not overcook so the beef remains tender. If the pan is too small, do this in two batches. Remove the beef from oil and set aside.

In the same pan with oil, pour the liquid mixture and let it simmer for 5-7 minutes or until the sauce is reduced and becomes thicker.

Add the pre-cooked beef and carrots and cook for another minute or two just to let the flavor seep in.

Garnish with sesame seeds and chopped green onion and serve with rice.